Protection of splice assemblies from the adverse effects of water remains one of the most important considerations in installing and repairing signal and energy transmission service lines. Such protection is particularly important today because the overwhelming trend is to place such service lines beneath the ground.
Several methods have been employed to protect splice assemblies. For example, greases and grease-like encapsulants have been used. However, these materials generally lack any three dimensional structure and/or elongation properties. Consequently, they tend to flow away from the splice area they are intended to protect when they are subjected to elevated temperatures and external pressures such as gravity, ground pressure, water pressure, etc.
Gels and/or crosslinked sealants tend to overcome the problem of flow. However, the three dimensional nature of these materials renders them somewhat stiff, and this stiffness often precludes them from flowing around the splice adequately enough to provide complete encapsulation.
Two part encapsulates have also been proposed. While these materials generally provide complete encapsulation, they suffer from the disadvantage that they require the on site mixing of ingredients. This takes additional time, and requires special equipment and clean up. These steps all increase the cost and inconvenience of making the splice.
The above-described encapsulants suffer from yet another disadvantage. They entrap moisture that may enter the splice area. This exacerbates the problems caused by the moisture and accelerates deterioration of the splice.
Yet another approach is described in U.S. Pat. No. 4,639,483. This patent discloses a composition which employs a plasticizer (either a naphthenic or paraffinic oil), an aliphatic or an aromatic carboxylic acid, CaO or ZnO, optionally an elastomer which is soluble in the composition, and optionally a hydrophilic additive. When the composition comes into contact with water, the water and the oxide form a base which then reacts with the acid to form a soap which solidifies.